[D's Bimmer]

I have recently installed the following in my car with the hifi system:

JL Audio HD 900 amp

JL Audio W3v3 sub(corner trunk enclosure provided by Musicar)

Morel Hybrid components(will be added next week)

My question is what should I have the amp settings at ideally? I plan to keep the stock underseat woofers for the time being. Specifically, I am interested in the sub settings given I am keeping the underseat woofers. What should be the front component settings?

I have various postings and just want to be sure.

Thanks,

[kaigoss69]

I take it you are completely replacing the HiFi amp and are using full range balanced inputs from the head unit? If so there is one fly in the ointment. The front and rear channels of the amp can only be high-passed. This means you will not be able to band pass the underseats unless you use an external fmod filter.

Having said that, I'd recommend you start at 80hz LP for the sub, 24 dB slope. Reverse the polarity of the sub to reduce phase issues and have better up front bass.

High pass the underseats at 80Hz 24db.

High pass the fronts at 150Hz 24dB.

To set the gains, start at minimum (all the way counter-clockwise), set HU to about 45 clicks, and then increase the front gain until it gets about as loud as you can stand it. Then reduce the volume and bring up the underseats to where they blend nicely. Lastly, do the same with the sub. You can use an RTA for better results of course but beware that iphone mics are not accurate at all below 150Hz.